Conventionally, various types of animal excrement disposal materials are provided which change coloration by absorbing excrement. For example, Japanese Unexamined Patent Application Publication (JP-A) No. 2009-273418 discloses such an animal excrement disposal material.
The animal excrement disposal material disclosed in JP 2009-273418 includes a granule formed of fine vegetable fibers, a colored layer provided on a surface of the granule and a surface layer provided on a surface of the colored layer. The surface layer is formed of starch, super absorbent polymer and pulp.
By provision of such a structure, the animal excrement disposal material of JP-A No. 2009-273418 exhibits white in a dry state, and its surface layer becomes translucent in a wet state, so that the color of the colored layer can be exposed. In this case, the wet state refers to the state in which pet excrement is absorbed.
In the animal excrement disposal material of JP-A No. 2009-273418, however, the colored layer and the surface layer may peel from the granule. Specifically, in a step of forming the colored layer, the granules and material for the colored layer are only agitated and mixed together in a rotary coating device. Further, the same method is only performed in a step of forming the surface layer.
Therefore, for example, when shipping the finished animal excrement disposal materials, the surface layer and the colored layer may peel off by rubbing of the animal excrement disposal materials against each other.